Supporting Information

Transcription

1 Supporting Information Engineering Lysosome-Targeting BODIPY Nanoparticles for Photoacoustic Imaging and Photodynamic Therapy under Near-Infrared Light Wenbo Hu, a Hengheng Ma, a Bing Hou, a Hui Zhao, a Yu Ji, a Rongcui Jiang, a Xiaoming Hu, a Xiaomei Lu, b Lei Zhang, a Yufu Tang, a Quli Fan, * a and Wei Huang* b a Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications, Nanjing , China. iamqlfan@njupt.edu.cn b Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing , China. wei-huang@njupt.edu.cn. S-1

2 Table of Contents in Supporting Information: 1. Figure S1: MALDI-TOF-MS spectrum of bis-styryl BODIPY dye. 2. Figure S2: Concentration dependence of the UV-Vis-NIR absorption of bis-styryl BODIPY dye in DMF. 3. Figure S3: Stability of the BODIPY NPs hydrodynamic size during different incubation periods with serum. 4. Figure S4: Dark-cytotoxicity of A549 and 3T3 cells after incubation with BODIYPY NPs at different concentrations for 24 h. 5. Figure S5: Fluorescence comparison of BODIPY NPs with bis-styryl BODIPY dye. 6. Figure S6: Mechanism of acid-activatable PDT. 7. Figure S7: The time-dependent photothermal curves of BODIPY NPs in aqueous solution under 730 nm continuous laser irradiation. S-2

3 Instruments. Mass spectra were obtained on a matrix-assisted laser desorption/ionization time of flight mass spectrometry MS (MALDI-TOF, Bruker AutoFlex III system). The lifetime were measured using an Edinburgh FLSP920 fluorescence spectrophotometer equipped with a picosecond pulsed semiconductor light (EPL375). The absolute fluorescent quantum yield were measured using an Edinburgh FLSP920 fluorescence spectrophotometer equipped with an integrating sphere. The photothermal experiments were conducted by IRS E50 Pro Thermal Imaging Camera (IRS Systems Inc, Shanghai). MALDI-TOF-MS spectrum Figure S1. MALDI-TOF-MS spectrum of bis-styryl BODIPY dye, which is highly accordance with Calcd C 66 H 73 BF 2 N 4 [M+2H]+: UV-Vis-NIR absorption of bis-styryl BODIPY dye in DMF S-3

4 Figure S2. (a) Concentration dependence of the UV-vis-NIR absorption of bis-styryl BODIPY dye in DMF. (b) The plot of optical density at 770 nm versus concentration. The straight line is a linear least-squares fit to the data, indicating the effective molar extinction coefficient of bis-styryl BODIPY dye at the absorption maxima. The insert table is the outcome of the linear least-squares fit. The UV-Vis-NIR absorption spectrum of bis-styryl BODIPY dye in DMF displayed a maximum absorption at 760 nm with a high molar absorption coefficient ε of M -1 cm -1 (Figure S2), suggesting it is an excellent NIR light absorber. The strong absorption in NIR region highlights the high potential of bis-styryl BODIPY dye as NIR-responsive PA contrast or therapeutic agents. Physiological stability of BODIPY NPs S-4

5 Figure S3. Stability of the BODIPY NPs hydrodynamic size during different incubation periods a) o h; b) 2 h; c) 4 h; d) 24 h with serum. No obvious change in hydrodynamic sizes suggests the excellent physiological stability of BODIPY NPs in biological environment. The BODIPY NP s hydrodynamic size distribution in serum was measured to evaluate the stability of NPs in the biological environments 1. The BODIPY NPs (1 mg) were added to 50% fatal bovine serum (FBS, 5 ml) and 50% PBS (5 ml) and incubated at 37 C for 48 h. The sample was analysed at 0 h, 2 h, 4 h, and 24 h by DLS. After 24 h incubation, all the hydrodynamic sizes of PDI NPs still retained at around 35 nm and their polydispersities were not changed. Thus, we concluded that the NPs were stable in serum (Figure S4). Dark-cytotoxicity of BODIPY NPs S-5

6 Figure S4. Dark-cytotoxicity of A549 and 3T3 cells after incubation with BODIYPY NPs of different concentrations for 24 h. To explore the applications of nano-agent in biomedicine, the standard methyl thiazolyl tetrazolium (MTT) assay was employed to determine the dark-cytotoxicity of BODIYPY NPs. No significant cytotoxicity was observed in Figure S5 even when the concentration of BODIYPY NPs was increased to 200 µg/ml, implying super low dark-cytotoxicity of BODIYPY NPs. Fluorescence comparison of BODIPY NPs with bis-styryl BODIPY dye. S-6

7 Figure S5. Fluorescence emission spectra of bis-styryl BODIPY dye in DMF and BODIPY NPs in aqueous solution. The strong fluorescence quenching indicating the high potential in PAI. Mechanism of acid-activatable generation of 1 O 2. S-7

8 Figure S6. a) Fluorescence emission spectra of 5 µm bis-styryl BODIPY dye in DMF and DMF/0.05 M HCL.Insert picture is the magnified sections of bis-styryl BODIPY dye in DMF. b) Fluorescence decay curve of bis-styryl BODIPY in DMF and DMF/0.05 M HCL recorded at max emission peak with an pulse laser at 375 nm. Black dot is the signals of instruction noise; Green line is the fitting of the fluorescence decay curve. Fit=A+B 1 exp(-t/τ 1 )+B 2 exp(-t/τ 2 ), τ=2.08 ns for bis-styryl BODIPY in DMF (red dot), τ=3.01 ns for bis-styryl BODIPY in DMF/0.05 M HCL(blue dot). c) mechanism of acid-activatable PDT. As known, a PS firstly creates an excited singlet state (S 1 ) upon excitation, and then undergoes photophysical pathway involves an intersystem crossing (ISC) from S 1 to excited triplet state (T 1 ). Finally, the long-lived triplet state interacts directly with molecular oxygen ( 3 O 2 ) to yield 1 O 2, which is the key cytotoxic agent in the therapeutic process to induce cell death 2-3. To verify the ability of bis-styryl BODIPY for controllably generating 1 O 2, the PL spectra and lifetime of bis-styryl BODIPY were determined since they are the direct presentation of excited singlet state. Without stimuli of H +, bis-styryl BODIPY in DMF showed a negligible fluorescence (Figure S6a), corresponding to a low absolute fluorescence quantum yield of 0.8% due to the efficient quenching of S 1 by a fast photoinduced electron transfer (PET) process at physiological ph. In sharp contrast, bis-styryl BODIPY in DMF/0.05 M HCL showed significantly increased fluorescence intensity (Figure S6a), corresponding to an increase in absolute fluorescence quantum yield of 12.4%, indicating the PET pathway would be switched off. This is because protonation of at acidic ph rendered the PET quenching process S 1 by lone pair electrons of -NMe 2, and thus leading to stronger fluorescence and higher absolute fluorescence quantum yield 4. From these results, we infer that, the generation of 1 O 2 is highly anticipated to be switched on upon the protonation of N atom at acidic ph (Scheme 1). Moreover, the enhanced lifetime of from 2.08 ns in DMF to 3.01 ns in DMF/0.05M HCL (Figure S6b) further revealed the switched off of quenching process and the potential switched on of 1 O 2 release. The mechanism of acid-activatable PDT was schematically illustrated in Figure S6c. In general, bis-styryl BODIPY dye has the potential as an acid-activatable PS to manufacture a cytotoxic 1 O 2 in response to one endogenous stimulus (microenvironment ph), which thus would switch on the therapeutic function in acid ph. Photothermal effects of BODIPY NP S-8

9 Figure S7. The time-dependent photothermal curves of 10 µg ml -1 BODIPY NPs in neutral and acid water under 730 nm continuous laser irradiation at the power density of 200 mw cm 2. No obvious temperature enhancement suggest the negligible photothermal effects of BODIPY NPs at such concentration and continuous laser power density. To exclude the photothermal effects to the cell viability, the time-dependent photothermal curves of 10µg/ml BODIPY NPs with power density of 200 mw cm 2 (the same laser power density for cellular PDT experiment) was performed. Even after 10 min laser irradiation, BODIPY NPs in either neutral or acid water exhibited negligible enhancement of temperature, indicative of the negligible photothermal influence to cell death. References 1. Kircher, M. F.; de la Zerda, A.; Jokerst, J. V.; Zavaleta, C. L.; Kempen, P. J.; Mittra, E.; Pitter, K.; Huang, R.; Campos, C.; Habte, F.; Sinclair, R.; Brennan, C. W.; Mellinghoff, I. K.; Holland, E. C.; Gambhir, S. S., A Brain Tumor Molecular Imaging Strategy Using A New Triple-Modality MRI-Photoacoustic-Raman Nanoparticle. Nat. Med. 2012, 18 (5), Dolmans, D. E. J. G. J.; Fukumura, D.; Jain, R. K., Photodynamic Therapy for Cancer. Nat. Rev. Cancer 2003, 3 (5), Dougherty, T. J.; Gomer, C. J.; Henderson, B. W.; Jori, G.; Kessel, D.; Korbelik, M.; Moan, J.; Peng, Q., Photodynamic Therapy. J. Natl. Cancer Inst 1998, 90 (12), Tian, J.; Ding, L.; Xu, H.-J.; Shen, Z.; Ju, H.; Jia, L.; Bao, L.; Yu, J.-S., Cell-Specific and ph-activatable Rubyrin-Loaded Nanoparticles for Highly Selective Near-Infrared Photodynamic S-9

10 Therapy against Cancer. J. Am. Chem. Soc. 2013, 135 (50), S-10